I/GCSE Biology - Clones and Stem cells

Do you remember the previous post regarding cloning of animal and plants in I/GCSE Biology? In this post, we are going to look at the clones and stem cells together!

Clones are:

• organisms that have identical genes
• It is an example of asexual reproduction:

1. Start with a body cell from an adult mammal and an egg cell from the same species
2. Enucleate (remove nucleus)
3. Put the DNA into the egg cell by fusing with an electric current to start mitotic division
4. The cell divides and is implanted in a surrogate mother

In I/GCSE Biology, the pros and cons of cloning are commonly asked in the exam!

Advantages:

• If the animal that is cloned has good features, all of its offspring will have the same good features
• Replacing pets
• Help save endangered species
• Could be used to make cells that treat diseases

Disadvantages:

• May take more attempts before a healthy cloned mammal is born, each attempt costs more money
• Cloned mammals may suffer more health problems than usual, may cause them to die early
• Any genetic defect in the parent will be passed onto the offspring
• Reduces gene pool (genetic variety)
• Some people think creating clones is like playing God

It's important to understand what stem cell is in I/GCSE Biology!

Embryonic stem cells:

• Cells in an embryo are unspecialized
• They divide to produce the differentiated cells in the body (differentiated = specialised)

Adult stem cells:

• Are found in differentiated tissue, such as bone or skin
• They divide to repair damaged cells

Research using stem cells:

• All stem cells
  1. Can replace faulty cell with healthy cell
  2. May produce cancer cells instead of healthy cells
• Embryonic stem cells
  1. Easy to extract from embryo
  2. Produce any type of cell
  3. Embryo destroyed when cell removed – some think embryos have the right to live
  4. Body recognises the cells as ‘different’ and will reject them without the use of drugs
• Adult stem cells
  1. No embryo destroyed so no ethical issues
  2. If taken from the person being treated, it will not be rejected by the body
  3. Difficult to find and extract
  4. Only produces a few types of cell

And we're done with this topic! Well Done!

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Drafted by Alyssa (Biology)

References:

1. "cloning", https://cdn.britannica.com/10/70110-050-8EF59E17/Dolly-process-sheep-somatic-cell-nuclear-transfer.jpg
2. "The pros and cons of cloning", https://www.farmonline.com.au/images/transform/v1/crop/frm/38U3JBx5nNussShT8aZyYjc/f520f80b-509e-4104-9669-582d5a7743a7.jpg/r4_0_1892_1067_w1200_h678_fmax.jpg
3. "Frontiers | Stem Cell Mechanobiology", https://www.frontiersin.org/files/Articles/597661/fbioe-08-597661-HTML/image_m/fbioe-08-597661-g001.jpg
4. "Human Embryonic Stem Cell Research", https://www2.le.ac.uk/projects/genie/images/project-related-images/Stem-Cells-the-promise.gif